Heretofore electrically powered lift trucks have been provided with hydraulic systems in which pressure fluid is supplied by a motor driven pump whenever a hydraulic valve is shifted from its neutral position to an operating position, this being accomplished by motor control switches associated with the valve control mechanism. This results in frequent running of the pump motor and considerable energy is consumed in starting the motor and accelerating the pump to its operating speed. In the prior art systems the entire pump output is at relief pressure and often only a small fraction of the pump output is used to operate the particular function.